Radiosignaling antenna system



Patented Jan. 18, 1927.

tenses PEDER OLUF PEDERSEN, OF FREDERICKSBERG,IDENMARK.

RADIOSIGNALING ANTENNA SYSTEM.

Application filed July 21, 1921, Serial No. 486,412, and in Denmark November 18, 1920.

The invention relates to radio signaling antenna systems and has for its object to diminish the high-frequency resistance of the aerials in wireless transmitting systems.

In high power radio transmission stations, the antenna must have a large capacity and must be placed at a rather great height and, therefore, must be of great extent. Such antenna are often built quite long in order to secure the required capacity at the lowest cost of construction, and in antennae of this nature it is very difficult to reduce the resistance to the desirable low value.

The present invention relates to an ar rangemont by means of which large antennae may be built with low resistance. When radio frequency current is delivered to the antenna at one or more points adjacent the generating plant or source of high frequency current, the total high frequency resistance is not represented by the resistance of the metallic circuit. One side of the source of high frequency current has been grounded and the other side connected to the antenna.

The great currents flowing in the antenna between the feeding point or points and the outer edges of the antenna cause currents of considerable magnitude to flow in the ground underneath the antenna and since the ground is a relatively poor conductor, these ground currents cause a power absorp tion and consequently an increase in the high frequency resistance.

According to the present invention, these undesirable currents flowing in the ground are eliminated by delivering the high frequency current to the antenna and to ground wires, through a number of feed conductors distributed equally over the entire area and so arranged that the currents in all of the various conductors where they enter the antenna or where they enter the ground, are in phase. The phase regulation is accomplished by inserting inductance in the feed conductors adjacent the generating plant. The creation of power absorbing currents in the ground or eddy currents in adjacent conductors by the current in the feed conductors, is prevented by bringing the two feed conductors. Since the currents in such pair of feed conductors, at any moment, are in opposite directions, they will neutralize each other with regard to distant inductive effect.

The invention possesses other advantageous features, some of which, with the fore going, will be set forth at length in the following description where I shall outline in full, that form of the invention which I have selected for illustration in the drawing accompanying and forming part of the specification. The drawing is a diagrammatic representation of a system embodying my invention.

The system comprises an antenna 2 which is suitably elevated above the ground, and the ground wires 3, forming a counter capacity, which may be in contact with the ground or insulated a short distance above the ground. The ground wires or counter capacity is preferably of the same extent as the antenna and is preferably located directly below the antenna. The source of radio oscillations, which may be any suitable radio oscillation generator 4, is connected to the antenna and to the counter-capacity at a plurality of spaced points, the points of connection being preferably arranged in pairs, with the point of connection to the counter capacity arranged directly below the point of connection to the antenna. The oscillationv generator t is connected to spaced points of the antenna by the feed conductors 5, 6, 7, 8 and 9 and to similarly spaced points of the ground wires b the feed conductors 5, 6, 7, 8 and 9. The feed conductors are arranged in pairs and at a certain moment the direction of the currents in the conductors is as indicated by the arrows. Arranged in each feed conductor is a variable inductance 12 by means of which the phase relations between the currents in the feed conductors are adjusted. F or the sake of simplicity in the drawing, the inductances in feed conductors 5, 5, 9 and 9 are not shown, but it is to be understood that variable inductances 12 are also arranged in these feed conductors. The number of feed conductors employed varies in accordance with the extent of the antenna. The various pairs of feeders are brought into the generating plant at a distance from each other which is generally large in comparison with the distance between the two wires of each pair.

I claim:

1. In a radio transmission system, an antenna occupying a substantlal horizontal area, a lower counter capacity, a source of osclllations, at least two antenna conductors,

connecting said source to said antenna at horizontally spaced points located unequal distances from said source, at least two counter capacity conductors connecting said source to said counter capacity at points substantially vertically alined with the points of connection to said antenna, and impedance means to cause, the currents at said several points of connection to be in phase.

2. In a radio transmission system, a source of. oscillations. an upper antenna, a counter capacity for the antenna and directly below the, same, a plurality of connections between the source and spaced points of the antenna, a plurality of connections between the source and spaced points of the counter capacity, these latter points corresponding in number and arrangement with those of the antenna, the connections to any pair of corresponding points being placed relatively near together, whereby absorption oi? energy due to eddy currents induced in the adjacent earth is minimized.

3. In a radio transmission system, a source. of radio. oscillations, an upper antenna, a lower counter capacity for the antenna and directly below the same, a plu rality of connections between the source and spaced points of the antenna, a plurality of connections between the source and spaced points of the counter capacity, these latter points corresponding in number and arrangement with those of the antenna, the connections of any pair of corresponding points being spaced relatively near together, and means for maintaining the same phase between the currents flowing into the antenna, comprising adjustable inductances in at least some. of the connections.

In testimony whereof, I have hereunto set my hand.

PEDER- OLUF PEDERQEN 

